Is my baby at risk of rubella infection?

Q:I am a 25 years old pregnant woman. During Rubella IgG and IgM tests, Rubella IgG level was found to be 52.7 and Rubella IgM level 0.44. This is my first pregnancy. How to prevent abnormalities and other complications to the fetus?

A:At the outset let me assure you that the reports you have sent of tests done during early pregnancy virtually exclude any risk of rubella to your fetus. From your tone I get the impression that you seem to feel that there is an added risk of an abnormality caused by rubella in your case. I am not sure how you got this impression as your tests virtually ensure that you cannot get rubella during pregnancy.

Rubella or German measles is a viral infection. It is a mild illness causing a rash and some fever only for a few hours to a day or two at the most. The problem is that if it occurs during early pregnancy, there is a very high chance of it causing serious abnormalities in the fetus including in the brain and the heart of the fetus. It is harmful to the fetus only if the pregnant woman contracts a new (acute) infection during early pregnancy, in the first five months or so. Like most viral infections, once a person gets the infection, he / she can never get the same infection, unless the person is on long term treatment with steroids, or immuno-suppressants after an organ transplant, or a serious disease like AIDS or cancer. So virtually there is no significant chance of getting the infection if you have already had it earlier.

I am not sure what stage of the pregnancy you are in, and why rubella was done (it is not often a routine test). Did you get an illness, which looked like German measles or was the test done as a ‘Routine’? IgG is now done as a routine to reassure the couple that this infection will not occur if woman is already immune, (IgG Positive).

IgG and IgM are two different Immunoglobulins, the levels of which increase as a defence mechanism of our body to fight against a particular infection. High levels in the blood of a person mean you have been exposed to this infection. The two, IgM and IgG behave differently. IgM increases in the blood as an initial response to a new infection (recent or as we say in medical jargon an “acute” infection) and if positive shows there has been a recent new infection. In your case that is negative. And as it takes months to come down, at least 6 months in case of Rubella, there is no risk that you would have got infection in the last few months, during the pregnancy.

IgG increases after weeks of a new infection and remains high for decades, and provides immunity against the infection virtually for a lifetime. In your case IgG is positive, over 50, meaning you either got the infection long ago or were vaccinated against it. In our country most of us get it during childhood and since it is a very mild infection lasting only a day or so, we never remember and even our mothers also do not recollect a rubella infection. We do an IgG test nowadays and if it is positive it means you are immune to Rubella, meaning thereby you cannot get it during pregnancy, which is good news.

From the reports you have sent it shows your fetus has no risk whatsoever of having an abnormality due to rubella.